body {
    margin: 0; /*边距*/
    background-color: black; /*背景颜色*/
    color: white; /*字体颜色*/
}

.panel {
    width: 75%; /*宽度*/
    margin: 50px auto; /*居中*/
}

#editor {
    width: 100%; /*宽度*/
    height: 300px; /*高度*/
    border-radius: 5px; /*圆角*/
}

.button-panel {
    display: flex; /*弹性盒*/
    justify-content: space-between; /*对齐方式*/
    align-items: center; /*居中*/
    margin-top: 10px; /*边距*/
}

.button {
    background-color: #4e4e4e; /*背景颜色*/
    padding: 10px 20px; /*内边距*/
    border: none; /*隐藏边框*/
    border-radius: 5px; /*圆角*/
    color: white; /*字体颜色*/
}

.dropdown {
    position: relative; /*定位*/
    display: inline-block; /*行内块级元素*/
}

.dropdown-content {
    position: absolute; /*绝对定位*/
    background-color: green; /*背景颜色*/
    border-radius: 2px; /*圆角*/
    top: 40px; /*边距*/
    right: 0;
    /* display: none; 隐藏 */
}

.dropdown-content a {
    padding: 10px; /*内边距*/
    text-decoration: none; /*下划线去除*/
    display: block; /*块级*/
}

/* .dropdown:hover 
.dropdown-content {
  display: block;
} */